1. Field of the Invention
The invention relates generally to high output power amplifiers and, more particularly, but not by way of limitation, it relates to an improved power generation apparatus for use as a current input source in induced polarization data acquisition systems.
2. Description of the Prior Art
In the past, two general types of power amplifiers have been used as induced polarization sources, i.e., power sources suitable for inducing relatively high current values into an earth medium at selected frequency and amplitude. One approach has been to generate a high D-C voltage and to polarity switch the voltage through the load, but such current inducement is limited to a square wave drive at the switching frequency. It has also been known to use specially designed and built D-C generators which are capable of being excited with moderate frequencies. Such units are able to respond to general purpose analog wave forms but are then limited as to the amount of output voltage available. Additional units may be placed in series to increase output voltage, but this then results in problems as to proper synchronization, excessive costs and bulky equipmentation.